Electric heater.



F,. KUHN.

ELECTRIC HEATER. APPLICATION FILED MAR. 29, 1912.

Patented May 19, 191i 'gTIIIII'll/[IIIflIIIIIIIIIIIIIIIIIIIIIIIII/IIIIIIIIIIIIIIII llI/llIl/II/F &

, eashes.

"UNITED STATES PATENT curios.

FRANK KUHN, or DETROIT, MICH GAN.

ELECTRIC HEATER.

Specification bf Letters iatent.

Patented M y 19, 1914,

Application filed March 29, 1912. SerielNo. 687,075.

Tan/1 IF/lt/HL- it may concern: Be it known that I,"FRANK Lilian, a c tizen of the United States of America, residing at Detroit, in the county of \Vayne and- State of Michigan, have invented certain new and useful Improvements in Electric Heaters, of which the followingis a specification, reference being had'therein to the accompanying drawings.

The invention relates to electric heaters and is more particularly adapted for use in connecti n with hot plates used in various cooking appliances and for. other similar uses. 1

It is an ob ect of the invention to hole the heating element in heat conducting contact with all portions of the plate and at the same time to avoid marring orinterrupting the surface of thehot'plate, and to reduce the thickness of the same to the minimum.

In the drawings,-Figure 1 is a perspec-.-

tive View of the hot plate, element and backing detached; Fig. 2 is a central section through the plate with the element clamped thereto and arranged in the supporting frame. Fig. 3 is a perspective view of the heating element, and Fig. 4 is a similar view of thejbacking plate.

A is a metallic plate having a smooth work surface B. On the opposite side from the work-surface area plurality of ro eot- .ing studs. 0 which are distributed over the area and are-used to clamp the element to .tially the same thickness and mass as the will securely fasten them thereto Without in any way injuring the work surface.

The element D'may be of any suitable construction but is preferably armored and is provided with terminals E which are fixedly secured in posit-ion. At various points distributed over the area of the element are apertures F therethrough which are positioned for registration with the studs C. i

G is a backing plate which is of substari *plate Jr and which is apcrtured lat H to corrcspond'to the a )ert:ures F and studsC.

Wheat-he parts are assembled the element "1" is firstp'laced in. contact with the plate and thcbackiug plate G in registration therewith. The clan'iping nuts I are tightened which will press all portions of the element in firm heat conducting contact'with the platcs i and G 50 that the heat gencrate-din the element will be uniformly dis.- tributcd theretln'ough.

and will also protect the element from overheating at any point which'might cause it to burn out 7 The plate 'A may be mounted on any suitable standard but as shown it is marginallysupported upon the cup-shap cd casing J which incloses the element and backing plate and forms a heat insulating air chamber 'l he plate 1s secured to the thcrcbeneath. casing by suitable means such as the shoulders K which engage the threaded. sockets.

in one or more of the lugs C as shown at L. The plate A is also preferably groovedor rabbeted about 1ts marg n as shown. M

This will preventuneven heating and warping of the'plat-e to form a, brake joint fit with the casing J V .which properly centers the parts and holds them from relative movement. The marginal flange of. the casing J is aperturedas at N to permit the terminal E to pass there'- thronghl \Vhat I claim as my invention:

1. ,In an electrical heater, the combination with a avrought metal heat-distributing plate, of an armored heating element formed as a unitary structure, a backing plate for said element, and a detachable connection between said heating element and 1 plates permitting the heating element to be detached as a unit from said plates, comprising studs distributed over the area of the heat-distributing plate and welded to, one

face thereof, said heating element having apertures registering with the studs and being in contact with the wrought metalplate and the backing plate also being provided with apertures registering ivith the studs, and detachable means cooperating with the studs for pressing the backing plate and element into heat-conducting contact with each other and with the heatvdistributing plate inall positions of the area of no the latter.

2. An electrical heater. comprising a,

wrought metal plate having a grooved or rabbeted margin, a plurality of threaded studs Welded to said plate and distributed over the area thereof, an armored electrical heating element placed adjacent to said plate within the grooved portion thereof and apertured for the passage of said studs, a backing plate correspondingly apertured, nuts engaging said studs for clamping said backing plate against said element, terminals on said element, a cup .-shaped casing having a marginal flange engaging the groove or rabbet of said plate, saidflange being apertured for the passage of said ter ininals, and securing screws for holding said plate in relation to said casing operable from the lower side thereof.

In testimony whereof I aflix my signature in presence of two witnesses.

FRANK KUHN. Witnesses HENRY F. KoLBE, ROLAND Dnmssnn.

Copies of this patent may be ohtaiiied for five cents each, by addressing the Commissioner of Iatents,

' Washington, D. C." v 

